it should be possible to do a calendar with a servlet, but just servlet on its own would cause the page to submit and refresh with every user interaction with it right. Maybe a pop up window then, but that uses javascript. And on that note, having a calendar choose widget in javascript would allow for a kind of dynamic HTML feature, improving the user experience (and possibly simplifying the operation by not requiring to pass all form parameters into the servlet for each calendar click operation).
I would recommend to try to find an existing Javascript calendar chooser API.
yeah actually after all attempts I decided to use javascript calendar, it looks more useful than servlet, refreshing page each time.
thank you for your support and suggestions.